Matte surfaced fluoropolymer films, such as polyvinyl fluoride, have been made by embossing or mechanically roughening the surface of the film as disclosed in U.S. Pat. No. 3,549,463 (Frech), U.S. Pat. Nos. 3,692,621, and 4,721,592 (Fruehauf et al.). Matte finished fluoropolymer films have also been made by casting fluoropolymer dispersions onto a polyester film support containing a deglossing agent as is disclosed in U.S. Pat. No. 4,931,324 (Ellison et al.). A cured, dry, matte fluoropolymer film is stripped from the supporting film. However, conventional methods are limited in that gloss levels are restricted to whatever deglossed polyester film is commercially available. Such conventional methods do not provide for tailoring or controlling gloss levels to meet custom end-use requirements.
Alternatively, matte surfaces may be obtained by adding a so-called deglossing agent to the fluoropolymer dispersion prior to casting onto a support as disclosed in U.S. Pat. No. 3,326,739 (Brennan et al.), U.S. Pat. No. 3,556,923 (Polejes et al.), and U.S. Pat. No. 3,397,108 (Hecht et al.). The presence of the deglossing agent in a fluoropolymer film typically results in hazy transparent films and changes the color of pigmented films. Additionally, the deglossing agent may contribute to discoloration of the fluoropolymer film during lamination or aging.
The disclosure of the previously identified patents and publications is hereby incorporated by reference.